Brush assembly



June 22, 1948. H. L. BURG BRUSH ASSEMBLIES 4 Sheets-Sheet '1 Filed Feb. 24, 1944 erLfiury wwn June 22, 1948. H. L. BURG BRUSH ASSEMBLIES 4 Sheets-Sheet 2 Filed Feb. 24, 1944 V J 3mm ffimenafiur June 22, 1948. H. L. BURG BRUSH ASSEMBLIES Filed Feb. 24; 1944 4. Sheets-Sheet Q5 4 She ets-Sheet 4 H. L. BURG Bausn ASSEMBLIES June 22, 1948.

Filed Feb. 24. 1944 o u m m mo am. am. am.

Patented June 22, 1948 UNITED STATES FATENT OFFICE BRUSH ASSEMBLY Homer L. Burg; Dallas City, Ill. Application February 24, 1944, Serial No. 523,714

1 Claim. 1

This invention relates to improvements in brush assemblies, and has particular relation to such assemblies used in heavy duty service, the invention being designed more particularly for use in connection with molding sand milling Y machine service, but can be utilized in other fields where the service conditions present heavy duty conditions. The present disclosure is based primarily upon the disclosureof my companion application for Molding sand milling machine, Serial No. 465,493, filed November 13, 1942, and allowed October '7, 1943, patented March 28, 1944, No. 2,345,457, in which the brush structure disclosed herein was partially shown and claimed, but the claim therefor withdrawn in view of office practice; certain additional features are being added in the present disclosure, and the application is therefore being filed as a continuation-in-part of such parent companion application.

To understand the characteristics of the problems which the present invention is designed to aid in solving, a brief reference is made to the service of the machine of the parent application,

a machine designed for service in foundries and the like. In foundry practice, where the castings are produced by the use of molds inwhich the mold is fashioned by the use of molding sand, it is essential that after the casting has been poured and later removed from the mold, that the sand be reconditioned; in earlier times this reconditioning was had by the workmen manually by shoveling or otherwise manipulating the sand of the heap, the latter being a lengthy line of sand piled up adjacent to the space in which the Workman provides his molding operation, a number of such lines being provided in spaced relation to place the sand convenient to the severa1 molders. During the conditioning manipulation, the sand remained in the linear arrangement, the workman simply displacing it within the line itself.

Later, machines were developed for providing the sand manipulation, one type-the cutting typeattempting to provide the action while retainin the sand in its linear locations, while a second type-ethe milling type, and which produced superior results-had the machine in fixed location, and required that the used sand be transported to the milling machine, reconditioned by the machine, and then returned to the linear positions, thus adding the handling of the sand to and from the machine as an added characteristic of the problems inv-o-lved.

The machine of the parent application pertains to the second type, so far as conditioning results are concerned, but is made mobile to enable the sand to be conditioned inits linear positions and thus avoid the necessity of transportation handling previously required by machines of the type. The machine of the application will be more fully described hereinafter, but at this point reference is made to the fact that the machine includes a brush formation which is rotated as the machine slowly advances along the heap, the brush rotation, provided by the advance, removing a thin increment of sand from the heap, the thickness of the increment being determined by the speed of machine advance, the increment of sand being thrown rearward and delivered into heap formation in rear of the machine. Hence, the sand is manipulated into its proper condition in situ, obtaining all the advantages of the milling practice, with its superior results, but eliminating the transporting and restoration into the heap formation.

Since the unconditioned sand of the heap left when the sand is removed from the molds by dumping, may have varied conditions such as the presence of small liunps, nails, etc., it is apparent that the'brush is subjected to difficult service conditions, being required to deal with a material (the sand) that issomewhat weighty normally, and which may be affected by the presence of the other abnormal conditions. In addition, the heap is somewhat triangular in cross-section, irregular in contour and surface, etc., thus providing more or less irregularity in the increment supply. As a result, the brush, which rotates at considerable speed, must be sturdy to withstandthe large strains placed upon itself; must be capable of producing the desired throwing speed to produce the conditioning action; and must be capable of withstanding as far as possible the wear conditions which are heavy since the ends of the bristles must continuously wipe over the static 'granular formation from which the thin increment is being re-' moved. In addition, the brush structure itself, due to the heavy duty conditions, maydeteriorate due to the continuous strains and other racking conditions to which it is subject in service, a condition which tends to render the structure les efficient; hence, the brush assembly must be so formed as to enable the overcoming of these conditions when they arise.

The primary object of the present invention is,

therefore, the production of a brush assembly- .designed for heavy duty service of the type indicated, and which is capable of ready replacement of brush material when wear conditions have rendered the assembly inefiicient; and to provide an assembly which is simple and efiicient in action, durable in construction, and which can be produced at moderate cost.

To these and other ends, therefore, the nature of which will be more clearly understood as the invention is hereinafter disclosed, said invention consists the improved constructions and combinations of parts hereinafter more fully described, illustrated in the accompanying drawings, and more particularly pointed out in the appended claim.

In the accompanying drawings, in which similar reference characters indicate similar parts in each of the views,

Figure 1 is a vertical longitudinal section. of, a milling machine equipped with a brush assem bly according to the present invention, the machine being shown in its service position.

Figure 2 is a top plan view of the same.

Figure 3 is a. rear elevation of the same with parts broken away.

Figure 4 is a fragmental diagrammaticsectional View indicating the assemblage in service.

Figure 5 is an end elevation, partly in section, of a preferred brush assembly.

Figure 6 is. a central longitudinal sectional view of the same.

Figure 7 is a diagrammatical view showing an illustrative arrangement of the bristle-like elements.

The milling machine, of which the present invention forms a vital element, is shown generally in Figures 1, 2 and3, although the claims therefor are presented in the parent companion application above identified; it is being disclosed herein to permit understanding of the characteristics of the problems being solved. The machine is shown in its service position relative to a heap. I-I (shown in dotted lines) The machine will be briefly described:

The machine includes, broadly, a traction unit presented by a pair of wheels ill mounted on a shaft l2, with the wheels spaced apart a distance sufficient to straddle the heap; a sandmilling unit, supported by the shaft; operating and control mechanisms by which the traction unit is driven, and the milling unitwhich includes the brush assembly-made operative; and elements by which the heapinitially of irregular formation, is preliminarily shaped by machine travel, to provide an approximately uniform presentation to the brush assembly during the advance of the machine.

A dominant characteristic of the machine is the fact that the milling unit, the operating and control mechanism, and the heap-shaping elements are formed and located so as to permit bodily swing about axle l2 through an arc of approximately 99, the extremes of the arc representing the active and inactive positions of the machine. The purpose of this is to permit the machine to be moved from heap to heap or to an inactive point by its own power, the operating mechanisms being such as to permit dirigibility of the machine by controlling the drive of the traction wheels individually. During service activities, the brush has its peripheral path practically tangent to the fioor levelbeing spaced slightly above such levela position which would be detrimental when moving the machine about the foundry; because of this it is necessary to shift the position of the brush sufficiently above the floor level as to avoid this difficulty and permit travel of the machine over the heap when the milling unit is inactive. The condition is met by bodily swinging the parts about the axle to a position at approximate right angles to that utilized during the service activities.

The milling unit includes a skeleton frame 23 supported on axle I2, with the frame having do pending side walls 13a spaced from wheels 58, and designed to provide a channel of definite width and within which the brush has its operation, the bottom of the walls approaching the floor level. The walls extend forwardly a suitable distance,

and at the. forward edges areprovided with 6.1-

verging. members, 330. designed toform a throat leading to the channelas the machine advances, these members 33a direct the excesswidth portion of the heapinto the channel. In addition, the frame carries a series of downwardly-extending fingers 3! which tend to form a rake-like structure designed to be advanced through the heap and discover and expose any castings which may have remained buried with-. in the heap. In addition, the frame carries an adjustable downwardly-extending plate 32 in advancev of the fingers and which serves tolevel off the top of the heap, thus assuring a practi cally; uniform depth of heap to be acted upon by the brush assembly, the excess simply moving down over the sloping sides of the heap within the channel; The frame also carries a pair of downwardly extending members 3 3 the lower ends-of which are turned rearwardly to form feet 3 m which travel in contact with the floor level in advance ofa vertical plane through the wheel axis, thus providing, with the wheels, means for supporting the unit on a substantally constant level in service.

These features provide for the preliminary preparation of the heap, and are necessary because of the fact that when the mold flasks are dumped after the castings have cooled, the heap produced is not only very irregular, but contains the-castings; when the latter are picked out, the irregularities may be increased. If the sand is to betreated to better fit it for re-use,

the additions are spread relative to such heaped sand. Hence, to permit of general uniformity in action, iii-becomes necessary to provide the preliminary actionsindicated in order that the brush activities will take place on an approximately uniform heap formation. In practice, the brush rotates at considerable speedpossibly 1000 R. P. Nit-and if. satisfactory service is to be had, the sand. should be delivered to the brush action as uniformly as the conditions will permit.

The brush, in service, constantly and continuously removes a thin increment of sand from the heapbefore it, the thickness generally depending upon the speed of advance of the machine, This increment. is swept rearwardlythe brush rotates clockwise in Figure 1-and the sand thrown forcibly rearward, generally into contact with a screen it; also carried by the frame-the screen is removable and may be omitted in some instances; the screen extends. upwardly arcuately or semispirally and terminates in a. pocket lBa designed to receive heap content which does not pass through the mesh of the screen. Hence, the actionof the brush in segregating the thin increments and throwing the particles rearward on to the screen 'willtend to produce a shower effect and provide a product of properly admixed sand particles which then become parts of the conditioned heap. To aid in shaping the latter and topre've'nt promiscuous splattering of particles in the foundry, the frame additionally carries an apron or hood ll which extends in rear of the screen and is formed with an open bottom; hence, the sand particles which pass the screen are confined within the small area defined by the apron,

arrests any flying particle, so that the particles drop down on to the developing heap, the top of*which'is determined by the lower bounds on theap'ion; since the greater height or the heap is in the mid-width zone, the conditioned heap will have a somewhat similar cross-sectional contour. since the brush will be removing a larger volume from this zone than from the side zones.

The frame l3 also supports a power unit positioned in the zone above shaft I2, and the brush assembly in the zone below such shaft-these locations being those occupied by these parts when the machine is in active operation; the axes of these elements, in such service locations lie generally on a vertical plane through the axis of shaft l2, with the remaining elements of the machine generally arranged at one side or the other of such plane. In other words, the various elements, including the speed reduction assemblage and the transmission connections, are generally so located and are of such weight characteristics, that the swingable portion of the machine is practically balanced relative to the shaft axis, although the balance is not accurate but approximate. The purpose of this is to permit ready swinging of the swingable portion about the shaft, although the machine itself is necessarily somewhat massive and weighty. In addition, the screen It is positioned to lie within the circular dimensions of wheels Ill to thereby permit the swinging action, it being understood that in swinging from active to inactive position, the swingable portion moves counter-clockwise in Figure 1; while apron "extends beyond such dimensions, the apron is of flexible type and capable of being rolled up and stored within such dimensions while the machine is out of active service position. Obviously the approximate balance of the machine will permit ready swinging through the approXimately right angular range between active and inactive positions.

The machine also carries various structures for meeting different possibilities in either position.

' For instance, while thepower unit serves to advance the machine bodily through controllable transmissions between the power unit and the wheels, the front of the machine is provided with steering means which permit an operator to control the direction of advance, and also the A application of the power to provide dirigibility, this being a part of the swingable unit; again 'a suitable supporting frame is positioned to be movable into a position to form a rest when the machine is in inactive position--swinging of the .e.

machine to inactive position includes the swin ing of feet 34a, and hence similar support is needed for maintaining the position of the machine in the inactive position.

In the form shown, the brush assembly is shown as driven direct from the power unit by belt 29a, with the brush shaft, in turn operative to drive the speed-reduction unit 22 located in the power zone through belt 42, unit 22 being operative to transmit power to the' crease in frictional resistance; in such case, the

particular arrangement will correspondingly slow up the rate of advance of the machine itself, with the result that the increment amount will not be materially changed by 1 1}? variations found in the heap,-

One other characteristic is present in that the power unit and the brush assembly are mounted on the frame in a manner to be adjustable vertically relative to the frame; this permits adjustments to be made for compensation for the brush diameter variations, without, however, affecting the operating connections-in service, wear of the bristles is inevitable; and the adjustable mounting permits proper compensation to be had.

The above description of the machine is designed as asetting to indicate the characteristics of the service to be performed and the extremely onerous service conditions which are placed upon the brush assembly and which must be solved to provide for efficient service conditions. Claims for the machine are not presented herein, as they are presented in the parent application above identified; the present application is designed to present the solutions provided in connection with the brush assembly per se. It is to be understood, of course, that the assembly is not limited to its use in this particular field, but is usable in other fields, and particularly those in which the service is of the heavy-duty typethe use in the field presented by this machine indicating one of the more severe fields of service for which the invention is adaptable.

The brush assembly I4, shown in detail in Figures 5 to 7, includes a shaft mounted in bearings 18a of the vertically-adjustable frame of the machine, said shaft 50 carrying the pulleys 2| and if! at its respective end zones, the former being driven from the power source through belt 28a, the latter being operatively connected with the speed reduction mechanism through belt 42 (the arrangements may provide for sprocketchain drive instead of belt drive). It is preferred that the mounting be such that the brush assembly can be readily removed bodily from its mounting, and/or that provision be made to permit portions of the assembly to be removed bodily from shaft 50 for servicing the brush assembly. Such arrangement makes possible the'ready removal of so much of the assembly as can be readily shipped to the manufacturer for the purpose of renewing the bristle zones, a service activity that is preferred since it enables the manufacturer to restore the assembly to its initial status in the most efiicient manner, after the bristle zones have become service worn, due to the heavyduty conditions. By utilizing a spare assembly to be substituted for the removed portions, the restoration can be made without affecting the usefulness of the machine, the restored assembly then becoming the spare upon its return.

Shaft 50 carries at the respective ends of the brush zones, a pair of spiders 5|, each of which may include a reinforcing band 52, and which, in turn, support an annular drum [4a which forms the support for the bristle-carrying elements l lc, these being in the form of bars extending longitudinally of the drum, with each bar carrying its bristles Mb. The width of bars Me is such as to provide a complete annular coverage for the druimthrough the number of bars employed, these being arranged in a particular manner to provide a particular result. In practice, the bars initially, if assembled into a complete circle, would present an internal diameter slightly greater than the external diameter of the drum. However, the final assembly is such that the inner faces of alternate bars will lie upon the drum Ma while the remainder bars will have their inner faces spaced from the drum, the side faces of the bars being proper y arranged-approximately radialto permit such assembly; The bars are secured in position by radial bolts or screws 53 which serve to unite the bars, drum, bands 52 and spiders i into a composite unit, some of the bolts or screws passing into the spokes of the spiders as well as the spider rim, while others reach only the rim.

This arrangement is provided to permit the assembly to be maintained in rigid formation. It is more or less inevitable that under the heavy duty service, atmospheric conditions, etc, there may be a tendency to develop loosen'ess. If the assembly of bars initially fitted the drum, this effect would tend to set up looseness, and could provide undesired stresses and strains on the bolts or screws due to the heavy duty being performed. By the particular arrangement indicated, tightening of the bolts or screws of the spaced bars would restore the tight Wedge-like action which produces the cylinder efiect upon the bar assem bly, doing this without disturbing the normal dimension conditions provided by drum Ma, since alternate bars rest in physical contact with the drum being held in such position by the bolts or screws.

As is apparent, if those bolts or screws which enter the spokes of the spiders are sufficiently withdrawn to release contact with the spiders, but remain in the drum, the drum and its bars can be slid axially from position, carrying the bars and bristles with it, and provide a unit which can be readily transported for purpose of restoration.

One of the features of the assembly is the zonal arrangement of the bristles. These can be formed of suitable material, but are preferably metallic in type to give them the service strength, and are suitably secured to the bars. However, due to the high. speeds employed (these may reach 1000B. P. M.) and the continuous abrading tendency of the sand produced as the bristle ends pass through the pile in the removal of the thin increment of sand, wear of the bristles is inevitable. And, due to the cross-sectional contour (approximate) of the pile, it is apparent that such wear will be greatest within the central zone of the .pile, due to the greater depth of the pile and therefore a longer period of wear development. Unless provision is made therefor, the brush contour would tend to become slightly concave, a condition which could obviously affect operation of the machine.

To meet this condition it is preferred to arrange the bristles with a zonal effect. For instance, as indicated in Figure 7, the central zone may have its bristle groups formed of, say, five bristles in close formation; on the other hand, the end zones may have the groups formed of three bristles, with the intermediate zones having the groups formed. of four bristles. These values are illustrative only and designed to meet the conditions of the particular service indicated; should the major portion of the work be differently located, the particular arrangement of the zones would be changed. And the same is true of the number of bristles of a group-with a less onerous service the number could be less, or the number as between zones may be varied. In other words, the assembly is designed to meet the conditions brought about by the varied abrading values 7 which may be encountered in service, the purpose being to retain as far as possible, the constancy of the substantially even length of the periphery. With the arrangement of Figure '7, the zonal wear will be approximately equal in this particular service, so that the length of the periphery will remain approximately even; wear will be present, but, in service, this condition is met by varying the height-adjusting mechanism of the machine.

As is apparent, the specific structure of the brush assembly, as disclosed, is more or less illustrative, since various changes or modifications of a more or less obvious type may be made therein without materially affecting the underlying feature of the invention set forth in detail above. I therefore reserve the right to make any and all such changes or modifications therein as may be found desirable or essential in meeting the exigencies of the service in which the invention is being used, insofar as the same may fall within thespirit and scope of the invention as expressed in the accompanying claim, when broadly construed.

Having thus described my invention, what is claimed as new is:

In brush assemblies for heavy duty service. wherein the brush is rotated by power drive to provide high peripheral brushing speeds during advance of the brush and its support, the combination of the brush drive shaft, of spaced spider formations carried thereby, and a plurality of bristle-carrying members each having its length extending in the general direction of the shaft axis, said members being arranged about and individually secured to the spider formations in two general series, the members of one series alternating with those of the other series to provide adjacent members from different series, the members of one series each having the inner face in contact with the spider formation periphery with the members of the other series spaced from such spider peripheries, the side faces of adjacent members being in abutting contact relation, whereby the combined series forms an annular formation rigidly mounted and maintainable in rigid service condition, the spider formations each including an annular member, the securing means for the members being capable of adjustment radially inward to provide rigidity of the annular formation, said securing means positioning all of the bristle-carrying members relative to the annular members and being operative to additionally anchor some of such bristle-carrying members to the spiders of the spider formations to provide drive of the brush from the drive shaft, release of the latter from the spider portion of the spider formation permitting bodily removal of the annular formation and the annular members as a unit.

HOMER L. BURG.

REFERENCES CITED The following references file of this patent:

UNITED STATES PATENTS are of record in the 

